JACKSON, Wyo. – A record-breaking heatwave has taken hold across the Western U.S. since late last week, shattering all-time September high-temperature records across the West, including Wyoming. Daily record high temperatures have been broken across Teton County as well.

On Sunday, numerous locations across Wyoming broke their all-time record highs for the month of September, a few of which were previously broken just a few days prior. Casper topped 100 degrees in September for the first time on record, with records dating back to 1939.

Here are some of the all-time September record highs that were set over the weekend.

All-time September record highs broken across Central Wyoming on Sunday, September 5, 2022.

In Teton County, Alta tied its all-time record high for September on Saturday with a high of 90ºF. Daily records were also set in Moose (92ºF), Moran (87ºF) and the Jackson Hole Airport (90ºF).

In the Town of Jackson, “official” NWS temperatures have exhibited an obvious under-reporting bias since about 2010 as evidenced by temperatures at surrounding stations. Based on the Hydrometeorological Automated Data System (HADS) weather station in Jackson, we likely tied a daily record on Saturday when the high reached 92ºF.

The heatwave will persist on Tuesday and Wednesday with highs expected to reach the low 90s in Jackson, both of which would set new daily records. The all-time record high for the month of September in Jackson is 93ºF, and we will come close to matching that on Wednesday before cooler air arrives on Thursday.

Alan Smith, Meteorologist

Alan is a professional meteorologist who holds a degree from MSU Denver and writes weather forecasts for Buckrail. He has lived in Jackson full-time since 2015. He is currently a Meteorologist and Operations Manager for OpenSnow, which is a weather forecasting service for skiing and outdoor adventures. At OpenSnow, Alan writes forecasts for the Tetons, Pacific Northwest, British Columbia, and North America as a whole.